As it turns out, I didn't have to make any of the suggested changes, and in fact, I was able to easily make a change so that utorrent performs exactly as it did before. Here is what I found out:
As of Firefox version 98, the downloads no longer open the "Add new torrent" page as part of utorrent. This is explained in the release notes for Firefox version 98. https://www.mozilla.org/en-US/firefox/98.0/releasenotes/
So what I did was to download a torrent, then right click on the download icon near the top right of my browser page. The torrent appears, and then I right clicked the torrent to open a menu. I select "Always Open Similar Files." From that point on, whenever you download a torrent, the "Add new torrent" page appears, and you can choose which files you want to download, as before. Select OK and the torrent appears on the main utorrent page. All just as before.